Seven major blazes, mostly in the west, have forced repeated evacuations, destroying homes and businesses.
Emergency crews rushed to Patras as a forest fire tore through mountain woodland towards an industrial zone.
Strong winds hampered operations on Zakynthos and Kefalonia, where officials stood ready to evacuate tourist areas despite no immediate threat.
Fires also raged in parts of the western mainland and on Chios in the eastern Aegean. Civil protection services issued over 20 evacuation and safety alerts nationwide on Tuesday.
